Dc powered solar tracker controller with heated battery

Abstract

A DC powered solar tracker controller for controlling an angle of inclination of a table of an associated solar tracker assembly. The controller includes controller electronics and a motor driver selectively energized to actuate the drive mechanism and thereby pivot the table of the associated solar tracker assembly. The controller further includes a rechargeable battery for powering controller electronics, the rechargeable battery charged by a controller power source, and a heating element controlled by controller electronics. The heating element is disposed in proximity to the outer surface of the rechargeable battery. The controller also includes a temperature sensor electrically coupled to the controller electronics, the temperature sensor disposed in proximity to the rechargeable battery. The controller electronics monitors the temperature sensor and, when the temperature of the rechargeable battery is within a predetermined range, the controller electronics actuates the heating element to provide heat to the rechargeable battery.

What is claimed is: 
     
         1 . A solar tracker controller for controlling an angle of inclination of a table of an associated solar tracker assembly, the table including a plurality of photovoltaic modules and the solar tracker assembly including a drive mechanism for pivoting the table through an angle of inclination range, the solar tracker controller comprising:
 a) controller electronics including a motor driver controlled by the controller electronics, the motor driver electrically coupled to the drive mechanism of the associated solar tracker assembly and selectively energized by the controller electronics to actuate the drive mechanism and thereby pivot the table of the associated solar tracker assembly;   b) a rechargeable battery for powering controller electronics, the rechargeable battery charged by a controller power source and having a minimum required operating temperature, the rechargeable battery including an outer surface;   c) a heating assembly electrically controlled by the controller electronics, the heating assembly disposed in proximity to the outer surface of the rechargeable battery; and   d) a temperature sensor electrically coupled to the controller electronics, the temperature sensor disposed in proximity to the rechargeable battery, the controller electronics monitoring an output signal of the temperature sensor indicative of the temperature of the rechargeable battery and, when the temperature of the rechargeable battery is within a predetermined value of the minimum required operating temperature, the controller electronics actuating the heating assembly to provide heat to the rechargeable battery to maintain the temperature of the rechargeable battery at or above the minimum required operating temperature of the rechargeable battery.   
     
     
         2 . The solar tracker controller of  claim 1  wherein the one or more photovoltaic modules of the controller power source includes one or more photovoltaic modules mounted to the table of the associated solar tracker assembly. 
     
     
         3 . The solar tracker controller of  claim 1  wherein the one or more photovoltaic modules of the controller power source includes a string of electrically coupled photovoltaic modules of the plurality of photovoltaic modules of the table of the associated solar tracker assembly. 
     
     
         4 . The solar tracker controller of  claim 1  further including insulation surrounding at least a portion of an outer surface of the rechargeable battery, the heating element disposed between the insulation and a first portion of the outer surface of the rechargeable battery and the temperature sensor disposed between the insulation and a second portion of the outer surface of the rechargeable battery, the first portion of the outer surface being space from the second portion of the outer surface. 
     
     
         5 . The solar tracker controller of  claim 1  wherein the controller electronics, the rechargeable battery, the heating element and the temperature sensor are disposed in a controller housing mounted to the table of the associated solar tracker assembly. 
     
     
         6 . The solar tracker controller of  claim 1  wherein the controller electronics are mounted in a controller housing and the rechargeable battery, the heating element and the temperature sensor are disposed in a battery housing. 
     
     
         7 . The solar tracker controller of  claim 1  wherein the heating assembly includes a thermally conductive material surrounding at least a portion of the outer surface of the rechargeable battery. 
     
     
         8 . The solar tracker controller of  claim 1  wherein the controller electronics includes a microcontroller, the microcontroller controlling the motor driver, the heating assembly and the temperature sensor. 
     
     
         9 . The solar tracker controller of  claim 1  wherein the solar tracker controller includes a second microcontroller, the second microcontroller controlling the heating assembly and the temperature sensor. 
     
     
         10 . The solar tracker controller of  claim 1  wherein the controller electronics actuates the heating assembly to selectively provide heat to the rechargeable battery to maintain the temperature of the rechargeable battery within a predetermined range at or above the minimum required operating temperature of the rechargeable battery. 
     
     
         11 . The solar tracker controller of  claim 1  wherein the minimum required operating temperature of the rechargeable battery includes a first minimum required operating temperature during daylight hours to enable charging the rechargeable battery and a second minimum required operating temperature during non-daylight hours to enable discharging the rechargeable battery, the first minimum required operating temperature being greater than the second minimum required operating temperature. 
     
     
         12 . The solar tracker controller of  claim 11  wherein the first minimum required operating temperature of the rechargeable battery is +2 degrees C. and the second minimum required operating temperature is −8 degrees C. 
     
     
         13 . A solar tracker assembly comprising:
 a) a table including a plurality of photovoltaic modules and a drive mechanism for pivoting the table through an angle of inclination; and   b) a solar tracker controller for controlling an angle of inclination of the table, the solar tracker controller including:   1) controller electronics including a motor driver controlled by the controller electronics, the motor driver electrically coupled to the drive mechanism of the associated solar tracker assembly and selectively energized by the controller electronics to actuate the drive mechanism and thereby pivot the table of the associated solar tracker assembly;   2) a rechargeable battery for powering controller electronics, the rechargeable battery charged by a controller power source and having a minimum required operating temperature, the rechargeable battery including an outer surface;   3) a heating assembly electrically controlled by the controller electronics, the heating assembly disposed in proximity to the outer surface of the rechargeable battery; and   4) a temperature sensor electrically coupled to the controller electronics, the temperature sensor disposed in proximity to the rechargeable battery, the controller electronics monitoring an output signal of the temperature sensor indicative of the temperature of the rechargeable battery and, when the temperature of the rechargeable battery is within a predetermined value of the minimum required operating temperature, the controller electronics selectively actuating the heating assembly to provide heat to the rechargeable battery to maintain the temperature of the rechargeable battery at or above the minimum required operating temperature of the rechargeable battery.   
     
     
         14 . The solar tracker assembly of  claim 13  wherein the controller power source includes one or more photovoltaic modules mounted to the table of the solar tracker assembly. 
     
     
         15 . The solar tracker assembly of  claim 13  wherein the one or more photovoltaic modules of the controller power source of the solar tracker controller includes a string of electrically coupled photovoltaic modules of the plurality of photovoltaic modules of the table of solar tracker assembly. 
     
     
         16 . The solar tracker assembly of  claim 13  further including insulation surrounding at least a portion of an outer surface of the rechargeable battery of the solar tracker controller, the heating element disposed between the insulation and a first portion of the outer surface of the rechargeable battery and the temperature sensor disposed between the insulation and a second portion of the outer surface of the rechargeable battery, the first portion of the outer surface being space from the second portion of the outer surface. 
     
     
         17 . The solar tracker assembly of  claim 13  wherein the controller electronics, the rechargeable battery, the heating element and the temperature sensor of the solar tracker controller are disposed in a controller housing mounted to the table of the associated solar tracker assembly. 
     
     
         18 . The solar tracker assembly of  claim 13  wherein the controller electronics of the solar tracker controller are mounted in a controller housing and the rechargeable battery, the heating element and the temperature sensor of the solar tracker controller are disposed in a battery housing. 
     
     
         19 . The solar tracker assembly of  claim 13  wherein the heating element of the solar tracker controller includes a thermally conductive material surrounding at least a portion of the outer surface of the rechargeable battery. 
     
     
         20 . The solar tracker assembly of  claim 13  wherein the controller electronics of the solar tracker controller includes a microcontroller, the microcontroller controlling the motor driver. 
     
     
         21 . The solar tracker assembly of  claim 13  wherein the solar tracker controller includes a second microcontroller, the second microcontroller controlling the heating assembly and the temperature sensor. 
     
     
         22 . The solar tracker assembly of  claim 13  wherein the controller electronics of the solar tracker controller actuates the heating assembly to selectively provide heat to the rechargeable battery to maintain the temperature of the rechargeable battery within a predetermined range at or above the minimum required operating temperature of the rechargeable battery. 
     
     
         23 . The solar tracker assembly of  claim 13  wherein the minimum required operating temperature of the rechargeable battery includes a first minimum required operating temperature during daylight hours to enable charging the rechargeable battery and a second minimum required operating temperature during non-daylight hours to enable discharging the rechargeable battery, the first minimum required operating temperature being greater than the second minimum required operating temperature. 
     
     
         24 . The solar tracker assembly of  claim 23  wherein the first minimum required operating temperature of the rechargeable battery is +2 degrees C. and the second minimum required operating temperature is −8 degrees C. 
     
     
         25 . The solar tracker assembly of  claim 14  wherein the one or more photovoltaic modules of the controller power source includes one or more dedicated photovoltaic modules mounted to the table of the solar tracker assembly.